Mucocutaneous candidiasis is one of the most common manifestations of HIV infection occurring in up to 84% of HIV infected patients. Although topical and systemic antifungal agents are used to treat these infections, they do not eradicate colonization and have resulted in an alarmingly increasing rate of candidal resistance to major systemic antifungal agents. Photodynamic therapy (PDT) is a modality that involves the use of a photosensitizing agent and laser light to create oxygen radicals resulting in the destruction of cancer cells, bacteria, viruses as well as fungi. Several dyes commonly used in medical practice are excellent photodynamic agents i.e., methylene blue and toluidene blue. These agents in combination with the appropriate wavelength of light have resulted in the destruction of azole drug resistant candida species in vitro. The proposed research will attempt to establish the feasibility of PDT treatment with topical dyes as a means of treatment of mucocutaneous candidiasis in an animal model, demonstrating the effectiveness, case and minimal morbidity of this treatment. PROPOSED COMMERCIAL APPLICATION: The longterm objective of the proposed research is to develop PDT treatment devices with topical dyes as a primary treatment for mucocutaneous candidiasis in HIV infected patients. As this treatment has a different mechanism of action than topical and systemic antifungal antibiotics, it will also reduce the significant problem of developing fungal drug resistance.